GEARS??? just a couple of questions

[curt03]

i have an e99 7.3 and its lifted on 40s.. i currently have 3.73s.. what gears should i go to.. i was thinking 4.56s maybe??

what will be the pros and cons of changing my gears and what gears would be best for me?

[Tj Krawler]

A stock F-250 should be at 1823 RPM at 65. With your current setup I come up with ~1,500 RPM at 65 MPH. With 40s, 4.56 gears would put you at 1768 RPM at 65. Which would be similar to stock gears with a 33" tire. (1750 RPM)

If you tow a lot, you may want to go to 4.88, but that's a pretty big jump. 40s and 4.88s will be ~1900 RPM at 65.

Calculator I used.
Gear Ratio Calculator

I also have a program called GearCalc. It's really nice to use. Gives you graphs of RPM/speed, and text versions, and far more. GearCalc

[atvrider93]

4.56s would be a good ratio. I think its when you get to 4.56s that the ring gear and pinion begin getting small and thin. as long as you aren't doing anything too rough offroad you should be fine

[Tim_T]

I just put 4.88's on mine. It is night and day from my 3.73's. So much better for towing my trailer too. Im on 40's also. Let me know if you have any questions. I think its perfect for what I do.

[Raul@Stealth Automotive]

there are no Cons to re gearing your truck for larger tires... this is something that is a must have.

i had 40's with 4.30's and i liked the combo.. still had great highway fuel economy. if you tow i would go with 4.56

[93stang]

At what point do you need to regear? I have 37" tires and have thought about it, but what gear?